In the electronic component mounting device that mounts the electronic components such as a semiconductor chip on the substrate, a camera using a line sensor such as a CCD in which image pickup elements are aligned in rows has been widely used up to now as an image reader for correcting a position gap between the electronic components and the substrate at the time of mounting by image recognition. When the image is read by the line sensor, there is a need to conduct scanning operation of relatively moving an electronic component to be read, and the line sensor in a direction orthogonal to an element array direction. For that reason, in the arrangement of the line sensor in the layout within the electronic component mounting device, there is a need to set in advance a movement direction of a mounting head when conducting the scanning operation. In general, in the electronic component mounting device configured so that respective component supply units are arranged on both sides of a substrate transfer path, the line sensor is arranged so that the element array direction matches a substrate transfer direction (first direction), or matches a second direction orthogonal to the first direction. However, even when any one of the above-mentioned arrangements is applied as the arrangement of the line sensor, such an arrangement has advantages and disadvantages from the viewpoint of optimizing the efficiency of the component mounting operation by the mounting head.
That is, when the line sensor is arranged so that the element array direction matches the first direction, the scanning operation for reading the image is conducted by moving the mounting head in the second direction. In this case, since the mounting head can move in a shortest path from the component supply unit toward the substrate, it is advantageous that a movement distance becomes shorter. However, when two mounting heads that face each other through the substrate are provided as a component mounting mechanism, because interference is generated between the respective mounting heads depending on the operating state of the facing mounting heads, the scanning operation for reading the image cannot be always executed at an arbitrary timing. In this case, a loss time is generated by a standby time since the facing mounting heads complete the component mounting operation until the mounting head is retreated from the substrate.
On the contrary, when the line sensor is arranged so that the element array direction matches the second direction, the scanning operation for reading the image is conducted by moving the mounting head in the first direction. In this case, since the mounting head moves along the substrate transfer path to conduct the scanning operation, it is advantageous that the scanning operation is enabled regardless of the operating state of the facing mounting heads. However, the movement distance of the mounting heads in the scanning operation necessarily becomes longer, resulting in that a required time for reading the image is increased. In order to eliminate a disadvantage caused by thus fixing the array direction of the line sensor to one direction, there has been proposed a configuration using a camera in which two line sensors are combined together into a cross shape (refer to Patent Literature 1).